Concerned with software or hardware firewalls

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1answer
321 views

Is it possible to force client use TCP instead UDP for DNS queries?

Assume I am managing a firewall between DNS server and clients. Is there any way to force clients use TCP rather than UDP, so we can prevent DNS spoof types of DDoS attacks?
3
votes
1answer
148 views

Security of OpenVPN against sophisticated DPI solution

I'm planing to build a device (prototype) that act as a portable security gateway. To make this, I choosed OpenWRT running on Raspberry Pi with OpenVPN for VPN connection. My main purpose of this ...
3
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1answer
2k views

Expose web service in a secure manner

Requirement I have a web service I need to expose on the DMZ for external communication. The web service communicates directly with a critical database that sits on an internal net. Current ...
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5answers
183 views

Windows: Any method to enforce user confirmation before the browser opens a URL requested by an external desktop app?

A robust outgoing firewall will protect against desktop applications directly connecting to the internet without your permission. However, as the browser is a generally authorized application for ...
3
votes
1answer
908 views

Isolate a Virtualbox VM from local network [closed]

I have the need to isolate a virtual machine created with Virtualbox from the local network but I need to provide internet access to that machine. It is the first time that I face this kind of ...
3
votes
5answers
409 views

Enforcing personal firewall for OS X

We're currently doing PCI compliance, and one of the requirements is that mobile devices that have access to systems involved in processing card data have personal firewall software installed which ...
3
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1answer
117 views

SYN scan, determining scan vs large file upload

In a system attempting to detect SYN scans, one technique is to analyze the rate of change of (network packets sent from victim host per second). Processes such as uploading a large file would not be ...
3
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1answer
515 views

SSL VPN placement strategies

I wanted to know the advantages and disadvantages of placing an SSL VPN with respect to CIA in different locations: with firewall within the internal network within the DMZ Any reference also ...
3
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1answer
263 views

Why strip accept-encoding?

It seems that there are multiple "security" products which strip or mangle 'Accept-encoding' headers, thus forcing non-compressed responses from HTTP servers. I've been trying to imagine if there's ...
3
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2answers
595 views

1 PIX firewall, 2 routers, 2 switches. Please answer a couple questions about hack lab

I bought a bunch of cisco equipment for a project and I got 1 PIX firewall 2 switches and 2 routers This is my plan for a topology but I am new at this so I need help. I am basing this off the ...
3
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2answers
70 views

How to restrict access to the internet for some computers on the network?

I’d like to differentiate machines (or, possibly, users) on my small business network so that only some of them have access to the internet. The solution I’ve been using to this day is quite terrible: ...
3
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2answers
253 views

how can an attacker access a system through a compromised router?

Let's say an attacker gained access to the admin panel of a home router with port 21, 23 and 80 open. I mean the attacker has full control over the router, thus being able to port forward, etc... ...
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3answers
174 views

Segregating a Printer in my Enterprise Network

I have a EAP-TLS network at home which I've managed for some time now. I just got a new Brother HL-5470 printer so I can finally print things at home, which is really nice. The only problem is that ...
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2answers
3k views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
3
votes
1answer
975 views

HTTPS form submissions are blocked on corporate networks

We have an HTML form which is submitted via HTTPS. We've noticed that when the form is submitted on a home network, it seems to go through just fine. However, when the form is submitted on certain ...
3
votes
1answer
2k views

w00tw00t.at.ISC.SANS.DFind iptables fix - abusable?

It's only an idea. I've recently logged that my server is scanned by w00tw00t tools. I found many solutions to this, such as use of apache mod-security, fail2ban, etc.. The one I want to speak ...
3
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1answer
866 views

Mac sending hundreds of packets to gateway

I've got a user on my work network who brings her personal laptop (macbook) in for work. They've been having some horrendously slow network issues on everything past that hub, so I did some packet ...
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0answers
72 views

I'm looking for a decent book on network and infrastructure security [closed]

I'm currently looking for a decent book on network and infrastructure security (especially in the enterprise context). Could you point me to one or two recent books, please? Thanks a lot in advance! ...
3
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2answers
146 views

How would iOS or Android app “firewall” for extended permissions (location, etc) work?

I'm interested in blocking or reporting any application's usage of extended permissions, regardless if they are granted those rights, such as: GPS / Location / Wifi Radio signal data Telemetry My ...
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2answers
205 views

How common is port-knocking? [closed]

Today I read about port-knocking for the first time. It has been a pretty known concept for more than ten years, but I don't know anybody who uses it for their servers. How common is the usage of ...
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5answers
37k views

What is the difference between antivirus and firewalls

I need a brief explanation about the differences between antiviruses and firewalls
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5answers
645 views

How do a firewall's rules for individual programs work?

I kind of know that how a firewall's rules for IP/port work, but I have no idea how a firewall deals with individual programs. In other words, how does the firewall know a program wants to access the ...
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6answers
2k views

How do I prevent data from leaving my network?

I have a network of about 10 computers and I want to prevent sensitive data and source code leaks. To achieve that, I would like to block all file uploading / attaching. What are the options ...
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3answers
9k views

What, specifically, does the Windows Firewall do?

My understanding of the situation is that, when the Windows firewall is off, every port on the computer (all 65535 of them) is fully open. This means that any application running on the computer can ...
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3answers
2k views

How to block the websites on client machines

In our office we are blocking sites like Facebook, Twitter etc.The problem is that some of the users bypass our proxy and firewalls through external proxy sites like www.youhide.com or ...
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4answers
2k views

Best way to push data to a client without being blocked by firewall

I'm asking this question here since I think people on this forum probably have the best knowledge of firewalls and routers. Say I'm designing a multi-player game and I want to push data to the client ...
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3answers
149 views

Open ports with no services binded to them

I have been wondering, if a port is open for inbound connections on the firewall yet there is no service binded to it, would that be considered a security vulnerability?
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2answers
7k views

How secure is blocking all incoming connections on my ADSL or cable router?

My router, an up-to-date ADSL Fritz!Box 7340 router with a fixed leased IP address, has been configured to block all incoming traffic. Assuming, for the sake of argument, no extra security is ...
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2answers
658 views

Identify if files are being transferred from my computer over the internet

This may seem like a silly question to most, but... I recently has some spyware infected on my machine, which I have since gotten rid of. Using a couple of scanners (that come recommended on various ...
2
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2answers
970 views

Firewall & TCP Traffic

I have a question regarding network firewalls and TCP traffic. When a firewall rule is set to block either inbound traffic, outbound traffic, or both on a port, does that only apply to initial ...
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2answers
205 views

Access via http to other protocols and ports!

Our firewall only allows HTTP port 80 but we have detected that a user accesses some other protocols and ports that we deny in our firewall. We know that he has developed an application (Console ...
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2answers
342 views

Web Application Firewall Rules

For Network Layer Firewalls we have different sort of redundancy and consistency checks like rule shadowing, that can impact the performance of firewall. Do similar kind of checks can be applied on ...
2
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3answers
6k views

windows firewall turns OFF automatically

It seems pretty weird but for some reason, the Windows 7 firewall turns off. After I turn the firewall on in the control panel, it seems that it turns itself off when I go back to the control after I ...
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2answers
4k views

IPTables default security rules for a gateway/router?

On a router such as dd-wrt or tomato, what would be some default iptables rules? I am asking for rules on a router/gateway - For example; blocking SYN flood attacks, or XMAS attacks. The basic ...
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2answers
357 views

Google DNS in Firewall logs

I was viewing my firewall logs and come across the IP 8.8.8.8. Further check reveals it belongs to Google DNS. And such traffic has been going out from some of our LAN segment PCs. From here on, how ...
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3answers
1k views

How to prevent attacks to server

I have 3 CentOS server configured for my applications. Recently I recognized that there is so many attacks to my servers. I have so many logs about attempt to login to my servers using sshd from ...
2
votes
2answers
206 views

Expose the source code repository externally or allow VPN access?

To allow third party consultants, offshore developers and contractors working on the code, we can expose our Git repository externally. Or we can grant VPN access to the external parties and limit ...
2
votes
3answers
856 views

iptables: plaintext password protection

I'd like to find a way to block or restrict my access to the web-pages where my password is sent as a plaintext on the internet. Let's assume if I have the same password for all web-pages, is it ...
2
votes
2answers
356 views

Telnet port open on my router public IPv6 address

Recently I upgraded my home router into this one. It is a cheap one, but it has features I needed: IPv6 support and Gigabit Ethernet. So I decided to give IPv6 a try. I configured a Hurricane ...
2
votes
2answers
3k views

Is it not safe to open MySQL's port to the internet?

The consensus on this Server Fault question seems to be that opening port 3306 for MySQL is more dangerous than using an SSH tunnel to access MySQL. I would think that with strong credentials you ...
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2answers
3k views

How to block network scans with pfsense?

I am using pfsense as firewall, and I would like to know how I can stop network scans from enumerating open services and ports. Thanks
2
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1answer
754 views

How can the Google web crawler bypass portals?

This is a situation that I have encountered on a number of occasions. I will conduct a web search in Google, a link to a file (.pdf for example) will take you to that file on the server. It opens up ...
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2answers
256 views

Are there “LAN IPs” on the internet?

I have a home-made web application and thought that an easy way to secure it's administration interface would be to simply reject all IPs that arent from 192.168... Is this viable? is it possible for ...
2
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2answers
3k views

Benefits of REJECT over DROP on a single PC

Recently I learned about the difference between DROP and REJECT in a firewall. I understand that REJECT is better because it closes the connection immediately instead of waiting for timeout as DROP ...
2
votes
3answers
3k views

Is an outbound firewall connection 'safer' than an inbound

We're trying to determine if pushing data through a firewall is more safe than pulling it. The data will be from SSIS to SSIS through the firewall. An advisor here has suggested that pushing the data ...
2
votes
2answers
4k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
2
votes
1answer
242 views

Maximum protection on a computer network?

I would like to secure as much as possible a computer I am using to sync sensitive data files from work to my home pc. The syncronisation is being done by only 1 software is there a firewall to allow ...
2
votes
2answers
1k views

Why is my firewall blocking on some files but not others?

I'm behind a corporate firewall which restricts access to certain urls and most downloads. The download restriction is mainly on .exe(but it allows some exe files to be downloaded and I don't know ...
2
votes
2answers
30 views

Database Protection : External & Internal

My company is using a weird database setup and I can't really figure what it is adding in term of security. Our Setup Outside World [Firewall] DMZ – Web Server [Firewall] External Database ...
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1answer
53 views

Terms for input/output to and from a Firewall

Is there an official/standard term for the stream of data sent into or out of a firewall? Obviously the inbound traffic would be the traffic under surveillance, and the outbound traffic would be the ...